The USGS map that you post shows the 1980 Mt. St. Helens ash plume as floating East across Washington and Idaho, and essentially stopping at the Montana border. As someone who was a 16-year old high school student in Missoula, MT, at the time, I'd like to say that this is inaccurate.
Missoula and the areas around it were deluged by between .5 and 1 inch of fine ash, which covered everything. The entire town ground to a halt, because nobody knew what was in the ash, and because the air pollution readings (Missoula is one of those mountain towns that suffers from frequently poor air-quality due to temperature inversions) were exceeding the highest levels on the charts by a factor of ten. Even the local schools closed (and this is Montana - you don't close school for any normal "weather" conditions). I can remember literally hosing off the street outside my house with my siblings, all wearing surgical masks, which the local hospitals were giving out to those brave/foolhardy enough to venture out into the eerie and silent city.
2) Another dares raise the question: what are the CO2 implications of this whole volcano/ aviation mess? Since like me he is an aviation buff, he has mixed feelings about the results shown by InformationIsBeautiful, here:
3) Reader George Bazhenov, in Russia, answers this item with the reassuring news that the Nigerian spammers are still doing fine:
I read your subject article with interest because some time ago my spam box looked very much like yours but now it shows a lot of spam in English. I have no explanation of this. By the way, most Russian-language letters shown on the screenshot that you published offer inexpensive mail distribution, i. e., more spam.Secondly, the Nigerians are now operating in Russia - two of my friends who do not speak English have recently asked me to translate letters from Nigeria which they received via email.